It is possible that TCP connect() will fail if for example network
interface does not have IP address set. In this case we close
the connection during net_tcp_connect() but do not set the return
code properly. This looks in the application like the connection
succeeded even if it was not.
As the tcp_in() call in net_tcp_connect() might close the connection,
we just take extra ref count while calling tcp_in(). Otherwise we
might access already freed connection.
Before the fix:
net_tcp_connect: context: 0x80757c0, local: 0.0.0.0, remote: 192.0.2.2
net_tcp_connect: conn: 0x8087320 src: 0.0.0.0, dst: 192.0.2.2
tcp_in: [LISTEN Seq=1604170158 Ack=0]
tcp_conn_close_debug: conn: 0x8087320 closed by TCP stack (tcp_in():3626)
tcp_conn_close_debug: LISTEN->CLOSED
tcp_conn_unref: conn: 0x8087320, ref_count=1
net_tcp_connect: conn: 0x8087320, ret=0
After the fix:
net_tcp_connect: context: 0x80757c0, local: 0.0.0.0, remote: 192.0.2.2
net_tcp_connect: conn: 0x8087320 src: 0.0.0.0, dst: 192.0.2.2
tcp_conn_ref: conn: 0x8087320, ref_count: 2
tcp_in: [LISTEN Seq=1604170158 Ack=0]
tcp_conn_close_debug: conn: 0x8087320 closed by TCP stack (tcp_in():3626)
tcp_conn_close_debug: LISTEN->CLOSED
tcp_conn_unref: conn: 0x8087320, ref_count=2
net_tcp: tcp_conn_unref: conn: 0x8087320, ref_count=1
net_tcp: net_tcp_connect: conn: 0x8087320, ret=-128
Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
a41f625fab